Container Cap with Airtight Device

ABSTRACT

An airtight device for a container cap includes a container having a pouring portion defined therein. A filling tube is selectively inserted into the container via the pouring portion. The filling tube has an annular flange radially and outwardly extending from one end thereof. An airtight element is air-tightly mounted to the annular flange of the filling tube. A cap is mounted to the pouring portion in the container. A through hole is defined in the cap to allow the filling tube to extend through the cap during filling. A shelter mounted between the annular flange and the cap for closing the through hole in the cap after filling. The airtight device is conveniently to fill oil from the container because the operator only needs to inversely mount the filling tube such that the palms of the operator will not be soiled during mounting the filling tube.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an airtight device, and more particularly to an airtight device for a container cap that includes only one airtight element mounted therein.

2. Description of Related Art

A conventional filling tube assembly, U.S. Pat. No. 5,829,494 disclosed by Chun, in accordance with the prior art comprises a filling tube and a cylindrical connector connected with the filling tube. The cylindrical connector comprises a first outer thread at one end, a second outer thread at the opposite end adapted for threading into a threaded pouring portion of an oil tank, a collar raised around the periphery in the middle between the first outer thread and the second outer thread. A screw cap is provided to be screwed onto the first outer thread for closing the cylindrical connector. The filling tube is inversely inserted through the cylindrical connector; the second outer thread threading into a threaded pouring portion and the screw cap is screwed onto the first outer thread after filling operation such that the filling tube is hidden in the oil tank. The operator can easily drain the oil from the oil tank when the filling tube is inversely assembled again.

However, the filling tube is hidden in the oil tank and the screw cap closes the cylindrical connector to prevent the oil tank from leaking. The filling tube is dipped in the oil when the oil tank is slanted and the oil in the oil tank will flow to the pouring portion. Consequently, the operator must take the dipped filling tube out before inversely assembling the filling tube and filling oil. As a result, the operator's palms are soiled.

The threaded portions of the screw cap and the cylindrical connector may be transformed due to a collision such that a chink may be formed between the screw cap and the cylindrical connector. As a result, the oil in the oil tank will drip from the chink. Unfortunately, these collisions are almost always unavoidable.

For solving the above problem, Chun discloses two rubber seal rings mounted around the first outer thread and the second outer thread to prevent the oil tank from leakage. However, the rubber seal rings will raise the manufacturing cost. In addition, the rubber seal rings will be loosened after being used for a period of time and the loosened rubber seal rings may fall into and sink in the oil tank. It is difficult and troublesome for users to dredge up the sunken rubber seal rings from the oil tank.

A conventional self-venting spout, U.S. Pat. No. 6,863,098 disclosed by Blitz, in accordance with the prior art comprises a spout (14) that can be inversely inserted into a container. One end of the spout has a sealing disk (32) formed thereon and a stopper rib (42) is formed on the sealing disk. The stopper rib projects radially from the conduit center axis beyond the upper and lower container sealing surfaces (38, 40) and extends entirely around the outer circumference of the disc (32). The neck (24) of the container (12) air-tightly abuts against the sealing surfaces (24 b, 48) that are formed on the collar (16). In addition, a locking ring (56) is configured to cooperate with the cap-receiving lip (50) of the collar (16) to retain the cap (18) coupled to the collar (16) to prevent the container (12) from leakage.

The sealing surfaces of the spout, the pouring portion and the sealing surfaces of the collar are air-tightly connected to one another. However, for achieving the objective, the sealing disk and the sealing surfaces thereof must made of plastic material for the metal made container and the collar; otherwise, the container, the collar and the screw cap are made of plastic material. Consequently, the above elements are used for a plastic container and do not suit a container that is made of metal for an airtight objective.

The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional filling tube assembly and self-venting spout.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide an improved airtight device for a container cap, which is conveniently to fill oil from the container because the operator only needs to inversely mount the filling tube such that the palms of the operator will not be soiled during mounting the filling tube.

To achieve the objective, the airtight device in accordance with the present invention comprises a container having a pouring portion defined therein. A filling tube is selectively inserted into the container via the pouring portion. The filling tube has an annular flange radially and outwardly extending from one end thereof. An airtight element is air-tightly mounted to the annular flange of the filling tube. A cap is mounted to the pouring portion in the container. A through hole is defined in the cap to allow the filling tube to extend through the cap during filling. A shelter mounted between the annular flange and the cap for closing the through hole in the cap after filling. The airtight device is conveniently used to fill oil from the container because the operator only needs to inversely mount the filling tube such that the palms of the operator will not be soiled during mounting the filling tube.

The cap has multiple bosses formed on an inner periphery thereof and the multiple bosses surround the airtight element and engage an outer periphery of the airtight element such that the filling tube is connected to the cap when the cap is mounted to the pouring portion.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged perspective view of an airtight device for a container cap in accordance with the present invention;

FIG. 2 is a cross-sectional view of the airtight device for a container cap in accordance with the present invention;

FIG. 3 is an operational view of the airtight device for a container cap in accordance with the present invention;

FIG. 4 is an enlarged perspective view of a second embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 5 is a cross-sectional view of the second embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 6 is a cross-sectional view of a third embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 7 is a cross-sectional view of a fourth embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 8 is an enlarged perspective view of a fifth embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 9 is a cross-sectional view of the fifth embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 10 is an enlarged perspective view of a sixth embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 11 is a cross-sectional view of the sixth embodiment of the airtight device for a container cap in accordance with the present invention;

FIG. 12 is a first schematic view of the airtight device for a container cap in accordance with the present invention that is used for an oil tank; and

FIG. 13 is a second schematic view of the airtight device for a container cap in accordance with the present invention that is used for a pot.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and initially to FIGS. 1 and 2, an airtight device for a container cap in accordance with the present invention comprises container (1) having a pouring portion (11) defined therein. The pouring portion (11) is formed with an outer thread (not numbered). A filling tube (2) is selectively inserted into the pouring portion (11). The filling tube (2) has an annular flange (21) radially and outwardly extending from one end thereof. The annular flange (21) has a diameter slightly greater than that of the pouring portion (11). An airtight element (3) is mounted to the annular flange (21) of the filling tube (2). The airtight element (3) has a ring structure and an annular groove (31) defined in an inner periphery of the airtight element (3). The annular groove (31) is provided to receive a distal edge of the annular flange (21). A cap (5) is screwed onto the pouring portion (11) for holding the filling tube (2) and the airtight element (3) in place. A through hole (51) is centrally defined in the cap (5) to allow the filling tube (2) extend through the cap (5). A shelter (4) is disposed between the cap (5) and the airtight element (3) for closing the through hole (51) in the cap (5) after the filling tube (2) inversely inserted into the container (1) via the pouring portion (11). The shelter (4) has a raised portion (41) centrally formed thereon. The raised portion (41) has a diameter corresponding to that of the through hole (51) in the cap (5). The cap (5) sequentially forced the shelter (4) and the airtight element (3) due to the pouring portion (11) such that the two opposite sides of the airtight element (3) respectively securely abut against the periphery of the pouring portion (11) and the shelter (4) to provide an airtight effect between the periphery of the pouring portion (11) and the shelter (4) to prevent the container (I) from leakage.

With reference to FIG. 3, the cap (5) is detached from the container (1), the shelter (4) is removed and the filling tube (2) extends through the through hole (51) in the cap (5). The airtight element (3) similarly provides an airtight effect between the cap (5) and the periphery of the pouring portion (1) to prevent the container (1) from leakage when the cap (5) is screwed onto the pouring portion (11) again.

With reference to FIGS. 4 and 5, the airtight device for a container cap further comprises an airtight washer (6) disposed between the cap (5) and the shelter (4). The airtight washer (6) can absorb the strike from the cap (5) to prevent the shelter (4) from being transformed and prevent the container (1) from leakage when the cap (5) is struck by an improper force.

With reference to FIG. 6, the shelter (4) has a diameter slightly smaller than that of the airtight element (3). The airtight effect of the present invention will not be influenced when the cap (5) is stricken and the edge of the airtight element (3) is forced. In addition, the airtight effect from the airtight element (3) will not be influenced even the shelter (4) is forced and transformed. With reference to FIG. 7, the diameters of the annular flange (21) and the airtight element (3) are reduced such that the diameter of the airtight element (3) is equal to that of the shelter (4). Consequently, an annular space is defined among the cap (5), the airtight element (3) and the shelter (4) and an airtight ring (7) is received in the annular space. The airtight ring (7) is forced by the cap (5) and the airtight element (3) to provide a further airtight effect.

With reference to FIGS. 8 and 9, the diameter of the shelter (4) is smaller than that of the airtight element (3) and the shelter (4) has multiple protrusions (42) radially and outwardly extending from the shelter (4). The multiple protrusions (42) define a circumference that has a diameter equal to that of the airtight element (3) such that the shelter (4) is easily guided to a central position when the cap (5) is screwed onto the pouring portion (11).

With reference to FIGS. 10 and 11, the cap (5) has multiple bosses (52) formed on an inner periphery thereof and the multiple bosses (52) surround the airtight element (3) and engage an outer periphery of the airtight element (3) such that the filling tube (2) is connected to the cap (5) when the cap (5) is screwed onto the pouring portion (11). As a result, the cap (5) and the filling tube (2) are easily operated and the palms of the operator will not be soiled during mounting the filling tube (2).

With reference to FIGS. 12 and 13, the airtight device for a container cap in accordance with the present invention can be used on an oil tank, a pot or any containers that need the effect provided by the airtight device for a container cap of the present invention.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

1. An airtight device for a container cap, comprising: a container having a pouring portion defined therein; a filling tube selectively inserted into the container via the pouring portion, the filling tube having an annular flange radially and outwardly extending from one end thereof; an airtight element air-tightly mounted to the annular flange of the filling tube; a cap mounted to the pouring portion in the container, a through hole defined in the cap to allow the filling tube to extend through the cap during filling; and a shelter mounted between the annular flange and the cap for closing the through hole in the cap after filling.
 2. The airtight device as claimed in claim 1, wherein the cap has multiple bosses formed on an inner periphery thereof and the multiple bosses surround the airtight element and engage an outer periphery of the airtight element such that the filling tube is connected to the cap when the cap is mounted to the pouring portion.
 3. The airtight device as claimed in claim 1, wherein the shelter has a raised portion centrally formed thereon, the raised portion having a diameter corresponding to that of the through hole in the cap.
 4. The airtight device as claimed in claim 1 further comprising an airtight washer mounted between the cap and the shelter.
 5. The airtight device as claimed in claim 1, wherein the shelter has a diameter smaller than that of the airtight element.
 6. The airtight device as claimed in claim 1, wherein the shelter has multiple protrusions radially and outwardly extending therefrom, the multiple protrusions defining a circumference that has a diameter equal to that of the airtight element such that the shelter is easily guided to a central position when the cap is screwed onto the pouring portion.
 7. The airtight device as claimed in claim 1, wherein the container, the cap and the shelter are made of metal. 